Pigment.



,UNITED sTATEs PATENT orries.

ANSI]: Morra'rr, or I mnmnaroms, INDIANA.

No Drawing.

To all whom it may concern:

Be it known that I, Assn. MorrA'rr, a citizen of the United States,residing" at the city 'of' Indianapolis, in the county of Marion andState of-Indiana, have invented certain new and useful' Improvements .in

' Pigments, of which the following is a specification.

This invention relates toa composition of matter consisting of a pigmentcomposed of barium sulfate in a state of extreme subdivision.

The principal object ofgmy invention is to produce an extremely finelysubdivided barium sulfate in large quantities and in a very pure statedirectly from the natural mineral barium sulfate.

.It has long been well known that barium sulfate, when brought into'acondition of extremel fine subdivision, ma then be cleared rom allimpurities, as it 1s the finest imaginable powder and is not affected byany known acid. It is also well known to those familiar with the artthat the pigments produced by the methods now in use fail'to adequatelyanswer the purposes of an ideal covering pigment, such as is desired inpure white paint. Both of the best known methods, one a mechanicalmethod, and the other an indirect and costly chemical method, result inpurified barium sulthe fused or melted mixture is cooled, the' chlorid,being a soluble salt, may be dissolved out from the barium sulfate,which latter is insoluble and will thus, remain be.- hind in a state ofextreme subdivision, to

be prepared for commerce in any form, as

, packed.

requirements dictate.

In the foregoing paragraph, and in the succeeding parts of myspecification, I refer to the barium sulfate as being extremely finelysubdivided. This is a term which I use to indicate the extremesubdivision of the barium sulfate which I succeed improducing bymyprocess, to distinguish it from Specification of Letters rum. 1:.Patented Apr. 3, 1911. ib ucanon-nlease tember-rs, 1910. SeriaI'No.582,146.

the ordinary barium sulfate heretofore roduced by other methods. Theprincipal evidence of this extremesubdivision is found 1n the adequateand thorough covering power and complete opacity of my product when usedas a paint pigment.

My preferred method of treating barium sulfate is as follows: I take thenatural form of barium sulfate (variously known under the names ofbarite, barytes, heavyspar or tiff) and 'mix it suitably with sodiumchlorid, this being both an economical and eflicient solvent for bariumsulfate and having a low fusing or melting point. The temperature orpoint of fusionwill be high or low according to the proportion of sodiumchlorid in the mixture, and the roportion of sodium chlorid used is ofsuch uantity that the two salts will be in'molecdlar proportion, or' thesodium chlorid ma be in excess, so that the fused or melted a1 0y willbecome homogeneous at an early period.

The mixture of barium sulfate and sodium chlorid is heated in anappropriate vessel until fusion occurs, and is maintained in a state offusion until the alloy or solution is homogeneous or com lete. Uponreaching this complete state 0 alloy, the fused mixture is withdrawn andsuitabl cooled. The cooling process may be carrie out either by pouringthe mixture out to cool, or by pourmg it into water in a gradual stream;Whichever method is used, the congealed product is then boiled in waterto dissolve the alkaline chlorid and to precipitate the barium sulfate.The precipitate of barium sulfate thus remaining, by reason of itsinsolubility in water, is the extremely subdivided product sought for bymy process. As a final step in its production, it may be sintablytreated by a process of washing and bleaching.- Itis washed in a waterbath, to remove any impurities of a solid nature wh1ch may-remain, andmay be treated with small quantities of acid to remove any coloringimpurities. The urified barium sulfate may be drained and dried andsuitably The result produced by the process above set forth is a pigmentof superior quality,

especially suitable for use as a paint pigment. Extended ex riment hasshown the fact that a perfect p1gment, chemically produced and dividedto an exceptionally high degree, may be supplied to enter commerce at acost approximating $20.00 per ton. This product is derived from themineral or natural barytes or tiff and is the result entirely of theprocess hereinbefore described. Its cost of production is small, byreason of the comparative simplicity, and ease of installation, of theapparatus necessary, and by reason of the general commer. cialquantities in which the necessary solvent can be obtained.

I claim:

1. A pigment body consisting of barium sulfate precipitated from analloy of natural barium sulfate and an alkaline chlorid.

2. 'A pigment body consisting of barium sulfate precipitated from analloy of natural barium sulfate and sodium chlorid.

In testimony whereof I have hereunto aflixed lily/ signature in thepresence of two witnesses. ANSIL MOFFATT.

Witnesses:

WILLIAM, J HENLEY,

E. FRANK ESTES.

